Cape workers are just the bees’ knees at reproduction
● Thousands of virgin births take place every year in a vicious Cape matriarchy, and scientists who have found the gene responsible for the phenomenon say it could explain the origin of sex.
A gene in the Cape honey bee allows worker bees to lay eggs that produce only females … no sex required.
“Males are mostly useless,” said professor Benjamin Oldroyd, a behavioural geneticist at the University of Sydney, Australia, whose research team has identified the gene.
“But Cape workers can become genetically reincarnated as a female queen and that prospect changes everything.
“Instead of being a co-operative society, Cape honey bee colonies are riven with conflict because any worker can be genetically reincarnated as the next queen. When a colony loses its queen the workers fight and compete to be mother of the next queen.”
The discovery of the gene was of more than academic interest. “If we could control a switch that allows animals to reproduce asexually, that would have important applications in agriculture, biotechnology and many other fields,” said Oldroyd.
And further study of Cape bees could provide insight into “two major evolutionary transitions: the origin of sex and the origin of animal societies”.
Reporting his team’s findings on Thursday in the journal Current Biology, Oldroyd said scientists had known about the Cape bee’s ability to produce daughters asexually, known as “thelytokous parthenogenesis”, for more than a century.
They had been hunting the gene responsible for the trait for about 30 years. “Now that we know it’s on chromosome 11, we have solved a mystery.”
Oldroyd said asexuality was a much more efficient way than sex for species to reproduce. “It’s a major biological mystery why there is so much sex going on and it doesn’t make evolutionary sense,” he said.
Cape worker bees, which are found mainly in the Western Cape, with fewer colonies in the Eastern Cape, also have ovaries that are larger and more readily activated than other species, and their ability to produce queen pheromones allows them to become dominant in a colony.
Oldroyd said these traits made them social parasites that invaded foreign colonies, reproduced there and used host colony workers to feed their larvae.
About 10,000 colonies of commercial beehives died annually in SA after Cape bee invasions, said Oldroyd, adding: “This is a bee we must keep out of Australia.”